package com.mapull.map;

import java.util.HashMap;
import java.util.Map;

/**
 * HashMap 示例
 * @author mapull
 */
public class MapullMap {

    public static void main(String[] args) {
//        checkMap();
        putNull();
    }

    private static void checkMap(){
        Map<String, String> map = new HashMap<>();
        map.put("1", "one");
        map.put("2", "two");
        map.put("3", "three");
        map.put("4", "four");
        map.put("5", "one");
        map.put("6", "two");
        map.put("7", "three");
        map.put("8", "four");
        map.put("9", "one");
        map.put("10", "two");
        map.put("11", "three");
        map.put("12", "four");
        map.put("13", "four");
        System.out.println(map);
    }
    private static void putNull(){
        Map<String, String> map = new HashMap<>();
        map.put(null, null);
        map.put("tom", null);
        System.out.println(map);
    }
}
